Zhan et al. present an interesting approach to substantiate the diagnosis of transient ischemic attacks employing venous blood gene expression patterns specific to this condition. [1]
The authors opted to classify the drugs used by their patients according to the drugs' clinical indications. This, however, may not be instructive for the research in question; rather, the authors should have categorized the drugs according to their ability to directly affect gene expression. Many commonly prescribed drugs including anticancer agents [2], anti-epileptic drugs [3], and corticosteroids [4] directly alter gene expression. No less than 13% of all FDA-approved drugs have nuclear receptors as their cellular targets. [5] Drug-induced inter-patient variability in gene expression has the potential to greatly confound the interpretation of changes in RNA profiles in everyday practice, and should be considered and controlled for in future studies aiming to utilize changes in such
patterns for disease diagnosis.
1. Zhan X, Jickling GC, Tian Y, et al. Transient ischemic attacks
characterized by RNA profiles in blood. Neurology;77:1718-1724.
2. Brown R, Strathdee G. Epigenomics and epigenetic therapy of
cancer. Trends Mol Med 2002;8:S43-48.
3. Rosenberg G. The mechanisms of action of valproate in
neuropsychiatric disorders: can we see the forest for the trees? Cell Mol Life Sci 2007;64:2090-2103.
4. Rhen T, Cidlowski JA. Antiinflammatory action of glucocorticoids -
new mechanisms for old drugs. N Engl J Med 2005;353:1711-1723.
5. Overington JP, Al-Lazikani B, Hopkins AL. How many drug targets
are there? Nat Rev Drug Discov 2006;5:993-996.
For disclosures, contact the editorial office journal@neurology.org.
Zhan et al. present an interesting approach to substantiate the diagnosis of transient ischemic attacks employing venous blood gene expression patterns specific to this condition. [1] The authors opted to classify the drugs used by their patients according to the drugs' clinical indications. This, however, may not be instructive for the research in question; rather, the authors should have categorized the drugs according to their ability to directly affect gene expression. Many commonly prescribed drugs including anticancer agents [2], anti-epileptic drugs [3], and corticosteroids [4] directly alter gene expression. No less than 13% of all FDA-approved drugs have nuclear receptors as their cellular targets. [5] Drug-induced inter-patient variability in gene expression has the potential to greatly confound the interpretation of changes in RNA profiles in everyday practice, and should be considered and controlled for in future studies aiming to utilize changes in such patterns for disease diagnosis.
1. Zhan X, Jickling GC, Tian Y, et al. Transient ischemic attacks characterized by RNA profiles in blood. Neurology;77:1718-1724.
2. Brown R, Strathdee G. Epigenomics and epigenetic therapy of cancer. Trends Mol Med 2002;8:S43-48.
3. Rosenberg G. The mechanisms of action of valproate in neuropsychiatric disorders: can we see the forest for the trees? Cell Mol Life Sci 2007;64:2090-2103.
4. Rhen T, Cidlowski JA. Antiinflammatory action of glucocorticoids - new mechanisms for old drugs. N Engl J Med 2005;353:1711-1723.
5. Overington JP, Al-Lazikani B, Hopkins AL. How many drug targets are there? Nat Rev Drug Discov 2006;5:993-996.
For disclosures, contact the editorial office journal@neurology.org.